Optical system alignment system and method with high accuracy and simple operation zP[_ccW@  
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Abstract E="FE.%A  
A system for aligning of optical components includes an interferometer and a first diffractive alignment element. A housing is used for positioning a first optical element being aligned. A detector is used for detecting fringes produced by reflections off surfaces of the first optical element. A grating pattern on the first diffractive alignment element is designed to produce a retro-reflected wavefront or a wavefront transmitted or reflected in a predetermined direction when the first optical element is in alignment. The first diffractive alignment element includes a first region for alignment of the interferometer, a second region for alignment of one surface of the first optical element, and a third region for alignment of another surface of the first optical element. The first, second and third regions can be of any shape such as circular, rectangular, triangular, or the like. 1r %~Rm  
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Inventors: Harned, Robert D.; (Redding, CT) ; Harned, Nora-Jean; (Redding, CT)  t")+L{  
Correspondence Name and Address:      STERNE, KESSLER, GOLDSTEIN & FOX PLLC @ P[o  
    1100 NEW YORK AVENUE, N.W. ,(%?j]_P2  
    WASHINGTON OI=LuWGQE1  
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    20005 q?Jd.r5*  
    US .*9+%FN  
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Assignee Name and Adress: ASML Holding N.V. c^N'g!on  
Veldhoven 8XwZJ\5  
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Serial No.:  938954 $Vu%4kq  
Series Code:  10  &) '5_#S  
Filed:  September 13, 2004 QQQ3
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